"Multitasking means screwing up several things at once," somebody once said, wrongly. In fact, we don't do many things at once, ever. We do many things in quick succession. And some of us are very good at it.Nagy-Bagoly Arpad/ShutterstockEverybody multitasks. We have conversations while driving. We answer email while browsing the Web. It's hard to imagine living any other way. What would be the alternative, removing the seats from your car to ensure you only drive alone? Block every website not named Gmail? A world of constant single-tasking is too absurd to contemplate.But science suggests th...

AN APOCRYPHAL tale is told about Henry Ford II showing Walter Reuther, the veteran leader of the United Automobile Workers, around a newly automated car plant. “Walter, how are you going to get those robots to pay your union dues,” gibed the boss of Ford Motor Company. Without skipping a beat, Reuther replied, “Henry, how are you going to get them to buy your cars?”Whether the exchange was true or not is irrelevant. The point was that any increase in productivity required a corresponding increase in the number of consumers capable of buying the product. The original Hen...